dimensionless quantity
quantity with no physical dimension
structure factor
mathematical description in crystallography
global warming potential
estimate of how an atmospheric gas affects global climate change
multiplicity
statistical weight of a quantum level
neutron number
number of neutrons in a nuclide
distance modulus
logarithmic distance scale
dissipation factor
ratio of dissipated to incident power
pressure coefficient
dimensionless quantity in fluid dynamics
logarithmic decrement
measure for the damping of an oscillator
void ratio
dimensionless quantity related to porosity
gross tonnage
nonlinear measure of a ship's overall internal volume
ratio
quotient of two numbers or quantities of the same kind
resonance escape probability
probability that a high-energy neutron is not captured
homologous temperature
temperature of a material as a fraction of its absolute melting point
power efficiency
dimensionless physical quantity; ratio of output power to input power
where-to-be-born index
index by the Economist Intelligence Unit
activity
measure of the effective concentration of a species in a mixture
characteristic number
quantity of dimension one formed by combining quantities describing a system or process
power factor
ratio of active power to apparent power in an AC electrical system
Miller index
describing crystal lattice planes
Euler characteristic
topological invariant in mathematics
traffic intensity
traffic engineering
instructions per cycle
measure of processing speed: the average number of instructions executed for each clock cycle
contrast sensitivity
ability of the eyes to detect sharp boundaries (stimuli) and to detect slight changes in luminance at regions without distinct contours
reflection coefficient
measure of wave reflectivity
average logarithmic energy decrement
average increase in lethargy per collision of neutrons with atomic nuclei
data compression ratio
measurement of the power of a data compression algorithm
relative permeability
property of porous media
relative density
ratio of the density of a substance to the density of water
mixing ratio
physical / meteorological quantity
relative molecular mass
ratio of the molecular mass and the unified atomic mass unit
rotation
physical quantity; number of revolutions of a rotating body or turns in a coil
maximum efficiency
efficiency of an ideal heat engine operating according to the Carnot process
mass percentage
percentage of one substance's mass to the mass of the total mixture
leaf area index
dimensionless quantity that characterizes plant canopies
atomic packing factor
fraction of volume in a crystal structure that is occupied by the constituent particles
Lorentz factor
factor 1∕√(1−𝑣²∕𝑐²) in special relativity expressing how much the measurements of time, length etc. change for a moving object
emissivity
effectiveness of an object in emitting thermal radiation
degree of dissociation
portion of dissociated molecules
volume fraction
dimensionless quantity
return on investment
ratio between the net profit and cost of investment resulting from an investment of some resources
volume ratio
physical quantity
millesimal fineness
dimensionless measure of fineness
magnetic pressure ratio
ratio of the plasma pressure to the magnetic pressure